The Argentina striker Sergio Agüero will miss the last-16 clash with Switzerland after suffering a muscle injury in his left leg and could be out of the World Cup should they progress.

Agüero’s injury in the 3-2 victory over Nigeria on Wednesday is a major blow to the South Americans’ campaign to capture a third World Cup, this time on the soil of their great rivals Brazil.

The team doctor, Daniel Martinez, told reporters the 26-year-old was undergoing magnetic resonance and other urgent treatments at the team’s camp in Belo Horizonte. “We have all the resources available to progress as quickly as possible,” he said. “He won’t be ready for the Switzerland game, and from there we’ll check his evolution day by day.”

Other sources close to the team said Agüero would almost certainly also be out for further games if Argentina progress.

The Manchester City forward, part of Argentina’s so-called Fab Four of strikers, was taken off during the first half of the match against Nigeria that gave them top spot in Group F.

Nicknamed Kun after a Japanese cartoon character, Agüero is a close friend of the national team captain, Lionel Messi, and is also the father of Diego Maradona’s first grandson. Argentina play Switzerland in São Paulo on Tuesday.

“We have forwards of the same style as Agüero and others, with a different style, like Lavezzi, who came in and handled himself well on the wings and helped us cover spaces,” the Argentina coach, Alejandro Sabella, said after the Nigeria game, where Lavezzi replaced Agüero.